Slacking Off...?

I really have no idea what's going on. In pretty much every class except calc, I've sort of been winging tests and stuff (the C on my last econ test should say something), and not really putting as much effort into homework/whatnot as usual... But my grades are pretty much as good as first semester... If they're lower, it's only by a percent or fraction of. It's rather confusing. Does this count as slacking off? xD Whatever, I'm not complaining. I can concentrate my efforts on calc then (bleurgh x.x).